Malicious PDF — malware analysis report

Static analysis result for SHA-256 6586543a0f38e264…

MALICIOUS

PDF

69.0 KB Created: 2021-10-03 11:21:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ead2a34ffafe19d84e6fc0a64dc1f10e SHA-1: 341d92daceb6b34ad77f7b032e2b6ac1516f4d67 SHA-256: 6586543a0f38e2646f504ae31a7913fe0d653606abcadee10bb01727971c46be
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to suspicious domains, suggesting a link farm or redirection mechanism. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports its use in distributing malicious content or phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://edu-family72.ru/content/images/uploads/file/vosozofeza.pdf In PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/63106902364.pdfIn PDF document text
    • https://aljazeerahdrilling.com/userfiles/files/98597377201.pdfIn PDF document text
    • http://greenmodels.ru/uploads/files/pomavepunas.pdfIn PDF document text
    • http://bielwod.com/userfiles/file/2191990632.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/36575095952.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1614d8dcc374e1---91132399472.pdfIn PDF document text
    • http://vaonhaphatphap.com/images/uploads/files/32173711985.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1615891f1dc1b4---3082011027.pdfIn PDF document text
    • https://photopoligrafic.ru/ckfinder/userfiles/files/tetizubakejotaxo.pdfIn PDF document text
    • http://tunapvietnam.thietbiotoviet.com/Images_upload/files/56319884377.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/zasagenem.pdfIn PDF document text
    • http://mitroc.com/userfiles/file/71541200670.pdfIn PDF document text
    • http://siltherm.com/ckfinder/userfiles/files/javikurosagixuvenawiwadar.pdfIn PDF document text
    • http://nhagiatxanh.com/public/default/ckeditor/files/31763792975.pdfIn PDF document text
    • https://doina.md/fckeditorfiles/file/sigojevafizusugipiv.pdfIn PDF document text
    • http://lammensfilip.be/uploads/files/pipabe.pdfIn PDF document text
    • https://5703n1n6999-6a55.com/contents/files/70037161711.pdfIn PDF document text
    • http://escuelasfutbol8.com/docs/files/rurutixemibirufowos.pdfIn PDF document text
    • http://thegioituigiay.net/uploads/files/wesufamogovojofibuparo.pdfIn PDF document text
    • http://gongin.humenia.com/upload/userfiles/2021/09/files/210922174703.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210927_00CF302EC8DAADE1.pdfIn PDF document text
    • http://moneymaker-gold.de/files/5577074909.pdfIn PDF document text
    • http://1careglobal.com/upload/files/rikadolulixukozuzumugejel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=ppap+training+material+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000af3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF3D 10552 bytes
SHA-256: 0d55f4c705cc4a837a36e286e20ca0f729ea9db898d06a0751b255bc36e851ff
font_01_sfnt_off0000c704.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC704 15384 bytes
SHA-256: a3b08f5c15aed57f961ef1ecb1d3e39ba627d93875d6d2fb4041715ebae07d04
font_02_sfnt_off0000ee48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE48 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1